Download ELG-2 Electron Gun

ELG-2 / EGPS-1022
ELECTRON GUN / POWER SUPPLY
1 eV to 2000 eV
Energy Sweeping: Constant Beam Current and Approximately Constant Spot
NEW LOWER ENERGY RANGE FOR IMPROVED RESOLUTION
FOR USE IN:
Surface Physics Studies
Electron Stimulated Desorption
Inverse photoelectron Emission
Ionization Experiments
Charge Neutralization
FEATURES / OPTIONS:
Wide Energy Range
Very Low Energies
Constant beam Current
Constant Spot Size
Zoom Lens Focusing
Demountable Gun
High Speed Pulsing
Deflection, Rastering
Computer/Remote Control
ELG-2A Electron Gun Mounted on 2¾CF Flange Multiplexer
The Kimball Physics ELG-2 Electron Gun, with its matching
EGPS-1022 Power Supply, is intended for use in electron stimulated
desorption studies, secondary electron emission coefficient
measurement studies, surface physics and other vacuum physics
studies. It is a complete subsystem ready to attach and turn on.
Firing units are user-replaceable; spare firing units can be purchased
new, and used firing units may be returned to the factory for rebuild.
Alternatively, the entire electron gun can be sent back to the factory for
complete cleaning, rebuild, cathode replacement, and optional
in-vacuum testing.
Beam energy, beam current and spot size are independently
adjustable over wide ranges. The energy is variable from 1 eV to
2000 eV, with a low range included for improved resolution at the
lowest energies. By use of multistaging and a computer-designed
electron zoom lens, a constant beam current is maintained over a twoorder-of-magnitude change in energy, with a spot size also roughly
constant. The gun can deliver 1 μA into an approximately 1 mm spot,
at a 2 cm working distance and 10 eV. The electron gun uses a
unipotential refractory cathode to generate a beam of low energy
spread.
The ELG-2 Electron Gun is available in two different mounting
configurations: as a standard mounted gun with a 2¾ CF Flange
Multiplexer, or as a demountable gun. The Demountable ELG-2 can
be used as mounted gun, or it can be removed by the user from its
mounting and used as an unmounted gun with the Flange Multiplexer
as a separate vacuum feedthrough.
UHV technology is used throughout. The gun can be run in vacuums
from 10-11 torr up to 10-5 torr for the standard Ta disc cathode. The
electron gun is bakable to 350°C with cables removed.
Optional cathodes include: barium oxide discs (BaO, low light, low
energy spread, min. vacuum 1x10-7 torr) and yttria-coated iridium discs
(Y2O3 - Ir, rugged, vacuum up to 10-4 torr, may survive brief loss of
vacuum). With the exception of BaO, the cathodes are not damaged
by repeated exposure to atmospheric gases or water vapor when cold.
Cathode lifetime is a function of vacuum conditions and beam current
as related to cathode temperature. Cathode lifetime at low currents in
good vacuum may be in the many hundreds of hours, or even over a
thousand hours.
EGPS-1022 Power Supply for use with the ELG-2A Electron Gun
Toll Free: 1 888 KIM-PHYS (1 888 546-7497) e-mail: [email protected]
Tel. 1 603 878-1616 Fax: 1 603 878-3700
The control grid allows either fast capacitive beam pulsing or optional
dual grid pulsing. Capacitive beam pulsing, using a Pulse Junction
Box, permits fast beam pulsing down to 20 ns with 20% maximum duty
cycle. Capacitive pulsing requires an external, variable-voltage pulse
generator (not included). Pulsing of the electron beam can also be
accomplished with dual grid supplies, requiring only a TTL pulse input.
A rastering option can be provided by an on-board power supply
module or as an additional feature in a LabVIEWTM software package.
The EGPS-1022 Power Supply features a modular design with
miniaturized power supply clusters, optically isolated signals, and the
new FlexPanel digital interface controller. The included power supplies
are Beam Energy and X,Y Deflection, as well as the floating
Source/ECC, Grid, First Anode and Focus supplies.
The new FlexPanel provides a digital display screen and a keypad for
programming control on the front panel. Rear panel connectors allow
remote /computer control and metering of all gun power supplies. An
RS-232 serial port and an analog input/output connector are included
on standard power supply units. All common computer interface bus
types can be accommodated, by use of appropriate digital to analog
converters. RS-422/485 conversion is possible.
An optional LabVIEWTM computer program designed for the ELG-2A is
available for remote computer control and metering. Software is
available in two types: Standard is via a simple serial connector
interface; an option is National Instrument DAQ boards and SCSI
connectors on the EGPS-1022. The program provides a virtual panel
of controls and real-time metering on the user’s computer screen.
2
ELG-2 ELECTRON GUN SPECIFICATIONS
BEAM ENERGY
BEAM CURRENT
ENERGY SPREAD
SPOT SIZE
WORKING DISTANCE
BEAM DEFLECTION
PULSE CAPABILITY
(using appropriate
pulse generator,
not included)
BEAM UNIFORMITY
FIRING UNIT
CATHODE TYPES
MOUNTING
FARADAY CUP
BEAM ALIGNMENT
INSERTION LENGTH
GUN DIAMETER
FEEDTHROUGHS
CABLES /
CONNECTORS
MAXIMUM BAKEOUT
EGPS-1022 ELECTRON GUN POWER SUPPLY SPECIFICATIONS
1 eV to 2 keV (Independently adjustable)
Standard: 1 nA to 10 μA (Independently adjustable)
Approx. cathode thermal spread, calculated
BaO - 0.3eV
Ta - 0.5eV
Y2O3 - 0.4eV
0.5 mm to 5 mm at 20 mm working distance
(Independently adjustable)
Range: 5 mm to 100 mm
20 mm recommended for very low energy operation
4 pole electrostatic: ± 2.5° at 2000 eV; scales larger at
lower energies
Capacitive Pulse Junction Box: pulse width 20 ns to
100 μs , rise/ fall 10 ns, 50 Ω impedance, 1 W standard
(higher power available)
Optional Dual Grid Power Supply: pulse width 2 μs to
DC, rise/ fall 500 ns, rep rates to 5kHz (TTL required)
Gaussian
Customer-replaceable Firing Unit includes
precision-aligned cathode and Wehnelt (G-1) assembly
and first anode, with insulators and connectors
Standard: Tantalum disc
Optional: Barium oxide (BaO) or Yttrium oxide (Y2O5)
With the exception of Barium oxide, cathodes not
harmed by repeated exposure to atmospheric gases
while cold
Flange Multiplexer with a 2¾ inch rotatable CF,
including both tapped and clear mounting holes
Optional: Demountable (Unmounted / Mounted) with
a Flange Multiplexer with a 2¾ inch rotatable CF
Gun mounted or stand-alone designs available
Optional: Mechanical alignment with ± 2° Port Aligner
Standard: 150 mm, Range: 110 mm to 170 mm.
Custom lengths available. Gun manufactured at standard
length unless otherwise specified at time of order.
25.4 mm at the gun flange, necks down to 19.1 mm at
100 mm from the flange
Multi-pin brazed ceramic, threaded stainless steel shell
Multiconductor high voltage fully ground-shielded cable,
coaxial grid cable, low voltage deflection cable, with
mating aluminum shell connectors, to connect gun and
power supply. Standard lengths: 3 m Optional: 5 m
350°C with cables removed
(Faraday cup: removable pneumatic actuator 65°C max)
OUTPUT
ENERGY STABILITY
BEAM STABILITY
All necessary voltages to drive the ELG-2 Electron Gun
±0.01% per hour; ±0.02% per 8 hours at full output
±0.1% per hour with Emission Current Control or
±10% per hour after warm up without ECC
CONTROLS
FlexPanel controls: Energy, Source, Grid, First Anode,
Focus, X and Y Deflection, Emission Current Control
METERING
FlexPanel digital meters: Energy, Hi / Lo Range, Source
Voltage, Source Current, Emission Current, Grid,
First Anode, Focus, X and Y Deflection
COMPUTER/REMOTE Power supplies: 0 to +10 V (-10 V to +10 V, deflection)
CONTROL & METER Metering: 0 to +2 V ( -2 V to +2 V, deflection)
Standard 50-pin connector for analog input/output and
RS-232 serial port (RS-422 or RS-485 available, if
specified at time of order)
Optional: SCSI metering and programming connectors
SOFTWARE
Standard configuration designed for RS-232
connections.
Optional: National Instruments LabVIEWTM file, designed
to run with computer DAQ boards NI PCI-6733 and
PCIe-6341. SCSI connectors
INPUT
115 VAC or 230 VAC, 50 to 60 Hz single phase, 250 VA
ENVIRONMENT
Temperature: 0 to 40ºC, Relative humidity: 0 to 75% RH
non condensing,
Classified as a pollution degree 2, installation category
(overvoltage category) II environment unit
17 in. x 3.5 in. x 22 in. excluding handles
DIMENSIONS
(425 mm x 90 mm x 560 mm); 19 in. rack mountable,
(width x height x depth)
added to main rack
OPTIONAL HARDWARE RASTER SPECIFICATIONS
RASTER GENERATOR
Continuous control of X & Y Raster Amplitude, variable
offset (Centering) and Frequency, with 0-10 kHz (X) and
0-100 Hz (Y) standard. All parameters controllable via
RS-232, RS-422, RS-485, analog input, or computer
control with LabVIEWTM software option.
DEMOUNTABLE ELG-2 ELECTRON GUN
Shown Mounted and Unmounted
(Dimensions in mm)
Typical performance;
data for guidance only.
Copyright© 2015 by Kimball Physics, Inc. 05/20/15
It is not necessarily possible to achieve all maximum specifications
simultaneously. Specifications Subject to Change Without Notice.